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Control Loader Software - USB

BFF Control Loader Software


UPDATE July '19: If you are a 3rd party software developer or would just like to try writing your own force feedback or specialist loading software a new CL Controller software app is now available which may be of interest. This app combines loading test functions currently provided in the Driver Test App with a new user loading data input mode to allow 3rd party software to drive the CL system cards.


For more details visit the CL Controller web page here....


BFF Control Loader SoftwareThe BFF Control Loader V2 software is used with our CL_SPU_USB and BLDRV3 motor driver cards in flight simulator flight control loaders.


It extracts live telemetry from FSX/P3D and X-Plane flight sims and instructs real-time loading of brushless drive motors in the flight controls.


Online User Guide



BFF CL Software V2 features

The flight control forces simulated by the BFF CL Software include:

  • Airspeed dependent aerodynamic loading (returning forces proportional to control surface displacement and airspeed)

  • Adjustable aerodynamic force gains (equivalent to adjustable control surface area)

  • Angle of attack (alpha and beta) effects (eg for longitudinal stability response)

  • Realistic GA trim behaviour (independent of simulator trim system, controls can be trimmed in any position) using trim potentiometers or trim buttons/switches.

  • Control surface static & dynamic weight effects (aircraft acceleration effects)

  • Prop-wash effects

  • Engine vibrations (vary with power & rpm)

  • Runway vibration effects (vary with runway speed)

  • Stall buffeting effects (frequency and amplitude definable - eg stick vibration type behaviour)

  • Damping and friction adjustments (-ve gains definable)

  • Auto Pilot following (native sim A/P only)

  • Separate configuration program with saveable configuration settings

  • Driver Test App for setup and commissioning

  • Helicopter cyclic trim loading mode.

  • Heavy Jet mode.

  • Sim-Avionics & ProSim, and also Failure Mode Loading.

  • Stick pusher effects.

BFF CL Configuration ManagerWhen used with the CL_SPU_USB + BLDRV3 brushless motor drivers the CL software exports flight simulator dependent force components at approximately 55Hz. These are added to the force components calculated onboard the BLDRV3 card at 500Hz. The on-board force processing of the BLDRV3 allows the CL software to run with minimal system resource which allows it to run on the same PC as the flight sim.


The included Configuration Manager application allows the configuration settings to be adjusted and saved in configuration files and to be updated in the main CL software as it runs. This allows the force effects to be tuned with the CL system active.





Runs on Windows 7+ PC's.


For FS9/X/2020 & P3D you will need an up-to-date version of Pete Dowson's FSUIPC installed. And for use with X-Plane 9.6+ you will need to install Torsten Spiering's XPUIPC v1.9.0 or later. For both see links to the right......




Control Loading Model


The loading calculation model has been developed to provide effective force demands for low cost self-build systems (compared to commercial control loader systems) and is principally based on the behaviour of GA aircraft with reversible controls. Additional modes are available for heavy jet operations. The model uses control axis position and velocity as the indicator of control surface position and velocity, this is measured at the brushless motor quadrature encoder. Airspeed, aircraft AoA, accelerations, engine condition, runway speed, stall state and other dynamic flight data are all taken live from the flight sim (FS9/X or X-Plane). Trim surface position is taken from the independent trim pot positions or trim button/switch operation.


Aerodynamic loads are calculated from control surface deflection and aircraft AoA and airspeed. The airspeed exponent used in the calculation of control surface lift can be adjusted to suit different control types. For small aircraft with controls mechanically connected to the control surfaces airspeed squared can be set. For fly-by-wire systems a linear relationship can be set (stiffness varies linearly with airspeed).


The model allows control forces to be calculated without the need to monitor applied loading and this greatly reduces the complexity and cost for self-build systems by avoiding the need for force sensors in the controls.


For Auto Pilot following the CL_SPU_USB + BLDRV3 cards switch automatically into a PID controlled position following mode and the CL software generates position demands based on the A/P control actions read from the flight sim. The A/P following can be disengaged by moving the controls or by the usual sim panel controls.


A/P following can be disabled if not required. Note that the A/P following functionality is active for the simulator software's native A/P system only - not for external A/P packages. UPDATE - A/P following for Sim-A and Pro Sim are now also available.





To operate effectively the software must be used in a properly designed and built system as described on the BLDRV3 page. The quality of the force feedback you obtain will be critically dependent on the quality of the design and build of the force transmission and other mechanical elements in your controls.




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